Currently, PCIE (PCI Express, peripheral component interconnect express) devices are applied rather widely, and interfaces of various PCIE devices are also applied widely in various fields. Interfaces of current PCIE devices are mainly of types such as an asynchronous Ethernet, an Infiniband, and a Fiber Channel (fiber channel). When working, such interfaces neither depend on a synchronous clock nor impose requirements on time synchronization and precision of the PCIE devices. With the convergence of the IT (Information Technology, information technology) and the CT (communications Technology, communications technology), the PCIE devices are required to support a synchronous network.
A reference clock in 100 MHz adopted by the PCIE devices has a very large difference from a reference clock of synchronous communications. In addition, no signal related to the time synchronization is defined in the PCIE regulations. In the prior art, a method for implementing the time synchronization among PCIE devices mainly includes: installing an independent synchronous device on each PCIE device, so as to achieve the clock and time synchronization among the different PCIE devices.
During the implementation of the present invention, the inventor finds that the foregoing method for implementing the time synchronization among the PCIE devices in the prior art at least has the following problem: each PCIE device needs an independent time serving device, which causes high cost and difficult maintenance of the PCIE device.